<!DOCTYPE html>

<head>
    <meta charset="UTF-8">
    <script src="../jQuery-3.6.3.min.js"></script>
    <script>
        (function ($) {
            $.fn.extend({
                "kalou": function (fgcolor, bgcolor) {
                    $("this").mouseover(function () {
                        $(this).css({ "color": fgcolor, "background": bgcolor });
                    }).mouseout(function () {
                        $(this).css({ "color": "orange", "backhround": "green" });
                    });
                    return $(this);
                }
            })
        })(jQuery);
    </script>
    <script>
        $(function () {
            $("h1").kalou("red", "green");
        })
    </script>
</head>

<body>
    <h1>hello</h1>
</body>

</html>